Amid the jubilation of a record-breaking home Olympics, there was one man who found success understandably difficult to stomach.

Aaron Cook, the world taekwondo No1 who was controversially overlooked for the Olympics, has revealed he was physically sick on the day he would have been competing at the Games and has vowed to switch nationalities if those responsible for his omission are not forced to resign.

Speaking in detail about his omission from Team GB for the first time, Cook said he would have seen the bronze medal secured by his replacement Lutalo Muhammad as "a disappointing loss" and claimed he had been "robbed" of a gold medal by the sport's governing body.

"I went to watch the taekwondo in London. It was extremely hard, extremely painful. I don't know why I did it. It was extremely hard watching people I've beaten convincingly this year get their Olympic gold medals and everything that goes with it," said Cook. "I didn't watch my day. I didn't watch Lutalo. I was in tears. I was sick. I couldn't watch it."

Cook, currently training in Washington, remains convinced he was overlooked for the Games because he split from GB Taekwondo's academy system to train on his own. He has written to the World Taekwondo Federation to ask it to ensure its world rankings count for more in determining selection for the Games.

If he fails to force change at the top of the sport's British governing body, he plans to switch nationalities to achieve his dream of winning gold at an Olympic Games. He said the "best case scenario" was that he would do so for Team GB, but that if those who overlooked him were not forced to resign he would follow through on the plan.

Cook and his team argued that he had beaten all of the best players in the world in the previous year and was ranked 58 places above Muhammad in his weight category.

But GB Taekwondo performance director Gary Hall argued that a key rule change gave Muhammad, who went on to win a bronze medal, an advantage.

The British Olympic Association forced GB Taekwondo to twice reconsider their decision to select Muhammad over Cook before finally agreeing that it had followed the correct procedure at the third time of asking.

Cook said that Muhammad's bronze, achieved through the repecharge after he lost in the quarter-finals to an eventual finalist, was "no vindication whatsoever" of GB Taekwondo's decision. "There are 16 athletes, four people get medals. I would have seen a bronze medal as a disappointing loss. He got to the quarter-finals and went out to a Spanish player that I had beaten three times. He got his opportunity and I congratulate him but I would have been there for the gold medal," said Cook.

Both the BOA and UK Sport have promised to force governing bodies to draw up more transparent, objective selection criteria ahead of the Rio Games. But Cook said that alone would not be enough unless the current GB Taekwondo regime was to quit.

"I want my Olympic gold medal. I was robbed of it in London and I'm not going to stand here and let these people rob it from me again in four years. If they stay in place we're going to have no option but to look elsewhere," said Cook.

"I don't trust them. Even with the biased selection criteria I was ahead. With them in place, there's no way to move forward.

"If there is no change I've got to look at changing nationality. If there is no change at the top, if Gary Hall and all the coaches are still there, there is no chance I would be selected or would want to be selected with them in charge," said Cook.

Cook claimed that despite Muhammad's bronze and a gold medal for Jade Jones, there needed to be a complete overhaul at the top of the sport.

"They've built their own empire with lottery funding and they've managed to scrape medals down the line. It's going to be difficult but I hope something good comes out of what happened to me and I hope it never happens to anyone else in any sport."